US20040243071A1 - Self-retaining needle - Google Patents

Abstract

There is provided an easily operated self-retaining needle capable of surely preventing accidental sticking of an inner needle, and touching to blood, humor or the like adhered to the inner needle. This self-retaining needle comprises an outer needle2, an outer needle hub4, an inner needle3and an inner needle hub6. An enveloping member8is provided for connecting a support member7for supporting the outer needle hub4with the inner needle hub6, and enveloping a front of the inner needle3. In the enveloping member8, a front portion10and a rear portion12are freely folded. When a knife point portion5is protruded from a tip of the outer needle2, the front portion10and the rear portion12are folded, and the rear portion12is housed between the inner needle hub6and the front portion10. When the inner needle3is retreated toward the rear of the outer needle hub4, the front portion10and the rear portion12are expanded along both side faces of the inner needle3. When a front portion23and a rear portion24are expanded along both side faces of the inner needle3, an enveloping member22envelops the inner needle3by the front portion23and the rear portion24.

Description

TECHNICAL FIELD
• The present invention relates to a self-retaining needle provided with an outer needle connected to an infusion device or the like, and an inner needle inserted into the outer needle to introduce the outer needle into a blood vessel or the like.[0001]
BACKGROUND ART
• A self-retaining needle has conventionally been known, which is connected to an infusion device or the like for introducing blood, medicine or the like into a body of a patient. The self-retaining needle includes a hollow outer needle connected to the infusion device or the like, and a hollow inner needle for introducing the outer needle into a blood vessel of the patient. When the inner needle is inserted into the hollow portion of the outer needle, its knife point is protruded from a tip of the outer needle.[0002]
• The self-retaining needle enables the outer needle fitted around the inner needle to be smoothly introduced into the blood vessel or the like by thrusting the knife point of the inner needle into the blood vessel or the like of the patient. After the introduction of the outer needle into the blood vessel or the like, the inner needle is pulled out, an infusion tube or the like of the infusion device or the like is connected to a hub of the outer needle in place of the inner needle, and then blood transfusion, medicine administration or the like is carried out.[0003]
• On the other hand, the inner needle that has been pulled out is disposed of. In this case, if the knife point is exposed, medical personnel or a worker engaged in disposal may stick the inner needle into a finger or the like accidentally (abbreviated to accidental sticking, hereinafter). Here, if the patient suffers from an infectious disease such as HIV or acute hepatitis, there is a possibility that the medical personnel or the worker engaged in disposal may be infected with the disease through the inner needle.[0004]
• Furthermore, blood, humor or the like of the patient is adhered to an outer surface of the inner needle. Thus, if the medical personnel or the worker engaged in disposal accidentally touches the blood, humor or the like, there is also a possibility that he may be infected with the disease.[0005]
DISCLOSURE OF THE INVENTION
• The present invention was made with the foregoing problems in mind, and it is an object of the invention to provide an easily operated self-retaining needle capable of surely preventing accidental sticking of an inner needle pulled out from a body of a patient for medical personnel or a worker engaged in disposal, and touching to blood, humor or the like adhered to the inner needle.[0006]
• In order to achieve the object, the first embodiment of a self-retaining needle of the present invention comprises a hollow outer needle, an outer needle hub provided in a base of the outer needle, a hollow inner needle having a knife point portion on a tip and a length of the knife point portion protruded from a tip of the outer needle when it is inserted from the outer needle hub into the outer needle, and an inner needle hub provided in a base of the inner needle and positioned at the rear of the outer needle hub when the knife point portion of the inner needle is protruded from the tip of the outer needle, comprises a support member for detachably supporting the outer needle hub in front of the inner needle hub, and an enveloping member for connecting the support member with the inner needle hub and enveloping a front of the inner needle when the inner needle is retreated toward the rear of the outer needle hub, wherein a front portion and a rear portion of the enveloping member are connected so as to be freely folded, the front portion is formed in a tub shape having a surface opposite the inner needle hub opened, and the rear portion is formed in a flat shape, when the knife point portion of the inner needle is protruded from the tip of the outer needle, the front portion and the rear portion of the enveloping member are folded, so that the rear portion is housed in the front portion formed in a tub shape, and when the inner needle is retreated toward the rear of the outer needle hub, and the front portion and the rear portion thereof are expanded along both side faces of the inner needle, the enveloping member envelops a front of the inner needle by the front portion.[0007]
• According to the self-retaining needle of the present invention, first, the inner needle is trust into a blood vessel or the like by the knife point portion of the inner needle protruded from the tip of the outer needle, and then the outer needle inserted over the inner needle is introduced into the blood vessel or the like. At this time, in the enveloping member, the front portion and the rear portion are folded at both side faces of the inner needle, and the rear portion is housed between the inner needle hub and the front portion. Thus, the enveloping member is prevented from interfering with the operation of sticking the inner needle into the blood vessel or the like, and introducing the outer needle into the blood vessel or the like,[0008]
• Then, when the inner needle is retreated toward the rear of the outer needle hub in order to pull out the inner needle and retain the outer needle, the front and rear portions of the enveloping member folded as described above are expanded along both side faces of the inner needle. As a result, at least a front of the inner needle is enveloped by the enveloping member.[0009]
• Therefore, according to the self-retaining needle of the present invention, it is possible to pull out the inner needle by the simple operation of retreating it after the outer needle hub. Moreover, according to the self-retaining needle of the invention, the above-described operation makes it possible to surely prevent medical personnel or a worker engaged in disposal from accidentally sticking the inner needle, or touching blood, humor or the like adhered on the inner needle.[0010]
• When the inner needle is thrust into the blood vessel or the like, mainly the front of the inner needle enters a body of a patient, and blood, humor or the like of the patient is adhered to this part. Accordingly, it is only necessary for the enveloping member to be capable of enveloping at least the front of the inner needle including the knife point portion causing a sticking accident. However, in order to further assure the prevention of the medical personnel or the worker engaged in disposal from touching the blood, humor or the like adhered on the inner needle, preferably, the enveloping member envelops the entire inner needle.[0011]
• According to the second embodiment of a self-retaining needle of the present invention, the self-retaining needle comprises a support member for detachably supporting the outer needle hub in front of the inner needle hub, and an enveloping member for connecting the support member with the inner needle hub and enveloping the inner needle when the inner needle is retreated toward the rear of the outer needle hub, wherein a front portion and a rear portion of the enveloping member are connected so as to be freely folded, the front portion is formed in a tub shape having a surface opposite the inner needle hub opened, and the rear portion is formed in a tub shape having a surface opposite the opened surface of the front portion opened, when the knife point portion of the inner needle is protruded from the tip of the outer needle, the front portion and the rear portion of the enveloping member are folded, so that the rear portion is housed in said front portion formed in a tub shape, and when the inner needle is retreated toward the rear of the outer needle hub, and the front portion and the rear portion thereof are expanded along both side faces of the inner needle, the enveloping member envelops the inner needle by the front portion and the rear portion. According to this constitution, since the enveloping member for connecting the support member with the inner needle hub envelops the inner needle by the entire combination of the front and rear portions, the entire inner needle positioned between the support member and the inner needle hub is enveloped by the enveloping member. Therefore, it is possible to more surely prevent the medical personnel or the worker engaged in disposal from touching the blood, humor or the like adhered on the inner needle.[0012]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a partially cutout plan view showing a self-retaining needle according to an embodiment of the present invention.[0013]
• FIG. 2 is a sectional view taken on line II-II of FIG. 1.[0014]
• FIG. 3 is an explanatory view of an operation of the self-retaining needle shown in FIG. 1.[0015]
• FIG. 4 is an explanatory view of an operation of the self-retaining needle shown in FIG. 1.[0016]
• FIG. 5 is a perspective view showing a state of an inner needle enveloped in the self-retaining needle of FIG. 1 with one side face of the inner needle omitted.[0017]
• FIGS. 6A and 6B are explanatory views showing protrusion preventing means of the inner needle in the self-retaining needle of FIG. 1.[0018]
• FIGS. 7A and 7B are explanatory views showing protrusion preventing means of the inner needle in the self-retaining needle of FIG. 1.[0019]
• FIGS. 8A and 8B are explanatory views showing protrusion preventing means of the inner needle in the self-retaining needle of FIG. 1.[0020]
• FIGS. 9A and 9B are explanatory views showing protrusion preventing means of the inner needle in the self-retaining needle of FIG. 1.[0021]
• FIG. 10 is a partially cutout plan view showing a self-retaining needle according to another embodiment of the present invention.[0022]
• FIG. 11 is a sectional view taken on line XI-XI of FIG. 10.[0023]
• FIG. 12 is an explanatory view of an operation of the self-retaining needle shown in FIG. 10.[0024]
• FIG. 13 is a perspective view showing a state of an inner needle enveloped in the self-retaining needle of FIG. 10 with one side face of the inner needle omitted.[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
• First, description will be made of a self-retaining needle[0026]1 according to a first embodiment of the present invention.
• As shown in FIG. 1, the self-retaining needle[0027]1 comprises a hollowouter needle2, and a hollowinner needle3 inserted into a hollow portion of theouter needle2. Theouter needle2 is provided with anouter needle hub4 on a base. Theinner needle3 is provided with aknife point portion5 to be protruded from a tip of theouter needle2 when it is inserted from theouter needle hub4 into the hollow portion of theouter needle2, and ainner needle hub6 positioned at the rear of theouter needle hub4.
• The self-retaining needle[0028]1 also comprises asupport member7 provided before theinner needle hub6 to detachably support theouter needle hub4. Thesupport member7 is fitted in theouter needle hub6. The self-retaining needle1 comprises anenveloping member8 provided to envelop a front part of theinner needle3 when thesupport member7 is connected to theinner hub6, and theinner needle3 is retreated toward the rear of theouter needle hub4.
• The enveloping[0029]member8 is arranged to be divided along both side faces of theinner needle hub6, and composed of a front envelopingportion10 rotatably attached to ahinge portion9 protruded in both sides from thesupport member7, and arear portion12 rotatably attached to ahinge portion11 protruded in both sides from theinner needle hub6. Thehinge portion9 is composed of arotary shaft9aprovided in a tip of thefront enveloping portion10, and a pair of upper and lower bearingsurfaces9bprovided in thesupport member7 to support therotary shaft9a. Thehinge portion11 is composed of a rotary shaft11aprovided in a rear end of therear portion12, and a pair of upper andlower bearing surfaces11bprovided in theinner needle hub6 to support the rotary shaft11a. The front envelopingportion10 and therear portion12 are connected to each other through athin portion13 so as to be folded.
• As shown in FIG. 2, the[0030]front enveloping portion10 is formed in a tub shape, where a surface opposite theinner needle hub6 is opened. Therear portion12 is formed in a flat plate shape. In a state where theknife point portion5 of theinner needle3 is protruded from the tip of theouter needle2, thefront enveloping portion10 and therear portion12 are folded at thethin portion13. In the above state, therear portion12 is arranged between the front envelopingportion10 and theinner needle hub6, and housed in the tub-shapedfront enveloping portion10.
• A[0031]gripper14 is provided on theinner needle hub6 to operate the same, and a diffusedair tube15 is connected to a rear end part of theinner needle hub6. The diffusedair tube15 is provided with a filter inside to ventilate air, and detachably fitted in the rear end part of theinner needle hub6 through a lure tapered portion at the tip. The filter operates to prevent contamination from the outside, and flowing-out of blood or the like when theinner needle3 is stuck into the blood vessel or the like.
• In place of the diffused[0032]air tube15, the filter may be arranged in theinner needle hub6 to prevent the flowing-out of the blood or the like.
• Next, an operation of the self-retaining needle[0033]1 will be described.
• In the self-retaining needle[0034]1, as shown in FIG. 1, thefront enveloping portion10 and therear portion12 of the envelopingportion8 are folded at thethin portion13, and therear portion12 is housed in the tub-shapedfront enveloping portion10. In the self-retaining needle1, first, in the above state, theknife point portion5 of theinner needle3 protruded from the tip of theouter needle2 is stuck into the blood vessel or the like of the patient. Then, theouter needle2 fitted around theinner needle3 is introduced from a rear side of theknife point portion5 into the blood vessel or the like.
• At this time, in the indwelling portion[0035]1, the envelopingmember8 is in the folded state as described above. Thus, the envelopingmember8 is prevented from interfering with the operation of sticking theinner needle3 into the blood vessel or the like, and introducing theouter needle2 into the blood vessel or the like.
• After the introduction of the[0036]outer needle2 into the blood vessel or the like, theinner needle3 is pulled out in order to connect an infusion tube or the like of an infusion device or the like to theouter needle hub4 in place of theinner needle3. At this time, medical personnel such as a doctor or a nurse grips thegripper14 provided on theinner needle hub6 while fixing theouter needle2 to retain it in its introduced state to the blood vessel or the like, and retreats theinner needle hub6.
• The[0037]front enveloping portion10 of the envelopingmember8 is rotatably attached through thehinge portion9 to thesupport member7, and therear portion12 is rotatably attached through thehinge portion11 to theinner needle hub6. Accordingly, when theinner needle hub6 is retreated as described above, following the retreating, thefront enveloping portion10 and therear portion12 are rotated toward theouter needle hub4. As a result, as shown in FIG. 3, thefront enveloping portion10 and therear portion12 are thrown out in sides of theinner needle3.
• Then, the[0038]inner needle hub6 is further retreated, and theknife point portion5 of theinner needle3 is retreated toward the rear of theouter needle hub4. Then, as shown in FIG. 4, thefront enveloping portion10 and therear portion12 are completely expanded along theinner needle3 on both side faces thereof to be linear.
• Thus, by removing the[0039]support member7 from theouter needle hub4, theinner needle3 can be disposed of. As described above, after the removal of thesupport member7, an infusion tube or the like of an infusion device or the like is connected to theouter needle hub4.
• As described above, in the self-retaining needle[0040]1 removed from theouter needle hub4, thefront enveloping portion10 and therear portion12 have been completely expanded. As a result, as shown in FIG. 5, on both sides of theinner needle3, the open surface of the tub-shapedfront enveloping portion10 faces theinner needle3, and the front part of theinner needle3 is enveloped by thefront enveloping portions10 and10. For explanation, only onefront enveloping portion10 is shown in FIG. 5.
• Thus, it is possible to surely prevent the medical personnel or the worker engaged in needle disposal from accidentally sticking the[0041]knife point portion5 of theinner needle3, or touching the front part of theinner needle3 on which blood, humor or the like of a patient is adhered.
• Also, on a rear portion of the[0042]inner needle3, since the flat plate-shapedrear portion12 is arranged in both side faces at this time, both upper and lower surfaces are opened only in width slightly larger than a thickness of theinner needle3. Accordingly, it can be made difficult for the medical personnel or the worker engaged in needle disposal to touch blood, humor or the like adhered on theinner needle3.
• In this case, the self-retaining needle[0043]1 comprises protrusion preventing means provided to prevent theknife point portion5 of theinner needle3 retreated into thesupport member7 once after theouter needle hub4 from being protruded from thesupport member7.
• When the protrusion preventing means is provided, for example as shown in FIG. 6A, by using the pair of upper and lower bearing surfaces[0044]11band11bas rotation guiding members, parts of the bearing surfaces11band11bare formed in slope shapes so as to be gradually protruded from surfaces. Then, a steppedportion11cprovided on a boundary with the surface of each of the bearing surfaces11band11bon a most protruded part of the sloped portion (slope portion) can be used as the protrusion preventing means.
• According to the constitution shown in FIG. 6A, in the state where the[0045]front enveloping portion10 and therear portion12 are folded as shown in FIG. 1, therear portion12 is positioned on a base (right end of the bearingsurface11bshown in FIG. 6A) of the slope portion. Then, following the operation of laying out thefront enveloping portion10 and therear portion12 as shown in FIG. 4 through the state of FIG. 3, therear portion12 is guided by the bearingsurface11b, and rotated from right to left in the drawing.
• Then, by going over the most protruded part of the slope portion, the[0046]rear portion12 is engaged with the steppedportion11c. As a result, therear portion12 is regulated by the steppedportion11c, and theknife point portion5 is prevented from being rotated again in a protruding direction (from left to right in the drawing).
• With the bearing[0047]surface11bas a rotation guiding member as shown in FIG. 6B, the protrusion preventing means may be a steppedportion11dformed from outside to inside on a side face of the bearingsurface11b. According to the constitution shown in FIG. 6B, as in the case shown in FIG. 6A, therear portion12 is rotated along the side face of the bearingsurface11bfrom a right end position to a left end position of the bearingsurface11bshown in FIG. 6B. Then, therear portion12 reaches the steppedportion11dto be moved from outside to inside of the bearingsurface11b, and engaged with the steppedportion11d. As a result, therear portion12 is regulated by the steppedportion11d, and theknife point portion5 is prevented from being rotated again in a protruding direction (from left to right in the drawing).
• As shown in FIG. 7A, with the pair of upper and lower bearing surfaces[0048]11band11bas rotation guiding members, the protrusion preventing means may be provided with agroove portion11ein thelower bearing surface11b, and a protrudedportion11fin theupper bearing surface11b.
• According to the constitution shown in FIG. 7A, when the[0049]front enveloping portion10 and therear portion12 are expanded as shown in FIGS. 4 and 5, therear portion12 is dropped into thegroove portion11e, and prevented from being pulled out by the protrudedportion11f. As a result, thefront enveloping portion10 and therear portion12 are inclined obliquely downward with thehinge portion11 as a basic point, inclining thesupport member7 with respect to an extended direction of theinner needle3 as shown in FIG. 7B. Thus, it is possible to prevent theknife point portion5 of theinner needle3 from being protruded again from thesupport member7.
• Further, as shown in FIG. 8A, the protrusion preventing means may be provided with a spacing[0050]member16ain thesupport member7. In this case, thesupport member7 includes ahousing portion7afor housing theknife point portion5 of theinner needle3, and asupport portion7bfitted over a tip of thehousing portion7ato support theouter needle hub4. When thesupport portion7bis fitted over the tip of thehousing portion7a, ahollow chamber17 is formed between it and thehousing portion7a, and the spacingmember16ais then provided in thehollow chamber17. The spacingmember16ais a cylindrical body provided with a through-hole18 for inserting theinner needle3 and, on one end, aground portion19 to be grounded to an inner wall of thesupport portion7b
• According to the constitution shown in FIG. 8A, when the[0051]inner needle3 is inserted from thehousing portion7athrough the through-hole18 into thesupport portion7b, the through-hole18 is in parallel with the extended direction of theinner needle3. However, when theinner needle3 is retreated and housed in thehousing portion7a, the spacingmember16ais only supported by theground portion19 on one end. Accordingly, as shown in FIG. 8B, the other end is brought into contact with the inner wall of thesupport portion7b, and the through-hole18 is inclined with respect to the extended direction of theinner needle3. Therefore, it is possible to prevent theknife point portion5 of theinner needle3 from being protruded again from thesupport portion7b.
• Further, in place of the[0052]cylindrical spacing member16ashown in FIG. 8A, the protrusion preventing means may be provided with aspherical spacing member16bas shown in FIG. 9B. The spacingmember16bincludes a through-hole18 on its spherical center. When theinner needle3 is inserted from thehousing portion7athrough the through-hole18 into thesupport portion7b, the through-hole18 is in parallel with the extended direction of theinner needle3. However, when theinner needle3 is retreated and housed in thehousing portion7a, the spacingmember16bis rotated in an optional direction and, as shown in FIG. 9(b), the through-hole18 is inclined with respect to the extended direction of theinner needle3. Thus, it is possible to prevent theknife point portion5 of theinner needle3 from being protruded again from thesupport portion7b.
• Next, description will be made of a self-retaining[0053]needle21 according to a second embodiment of the present invention.
• As shown in FIG. 10, the self-retaining needle[0054]1 is completely similar in constitution to the self-retaining needle1 of the first embodiment except the structure of the envelopingmember22. Thus, in the self-retainingneedle21, components similar to those of the self-retaining needle1 are denoted by similar reference numerals, and detailed description thereof will be omitted.
• The enveloping[0055]member22 is designed to connect asupport member7 with aninner needle hub6, and envelope an entireinner needle3 when theinner needle3 is retreated toward the rear of anouter needle hub4. Accordingly, the envelopingmember22 is arranged to be divided along both side faces of theinner needle hub6, and composed of afront enveloping portion23 rotatably attached to ahinge portion9 protruded in both sides from thesupport member7, and arear enveloping portion24 rotatably attached to ahinge portion11 protruded in both sides from theinner needle hub6. Thefront enveloping portion23 and therear enveloping portion24 are connected to each other through athin portion25 so as to be folded.
• As shown in FIG. 11, the[0056]front enveloping portion23 is formed in a tub shape, where a surface opposite theinner needle hub6 is opened. On the other hand, therear enveloping portion24 is formed in a sub shape, where a surface opposite the opened surface of thefront enveloping portion23 is opened. In a state where aknife point portion5 of theinner needle3 is protruded from a tip of theouter needle2, thefront enveloping portion23 and therear enveloping portion24 are folded at athin portion25. In the above state, therear enveloping portion24 is arranged between thefront enveloping portion23 and theinner needle hub6, and housed in the tub-shapedfront enveloping portion23.
• According to the self-retaining[0057]needle21 shown in FIG. 10, by an operation similar to that of the self-retaining needle1 of the first embodiment of FIG. 1, theknife point portion5 of theinner needle3 is thrust into a blood vessel or the like of a patient, and theouter needle2 is introduced into the blood vessel or the like. At this time, in the self-retainingneedle21, the front andrear enveloping portions23 and24 of the envelopingmember22 are folded at thethin portion25, and therear enveloping portion24 is housed in the tub-shapedfront enveloping portion23. Thus, the envelopingmember22 is prevented from interfering with the operation of sticking theinner needle3 into the blood vessel or the like, and introducing theouter needle2 into the blood vessel.
• Then, a[0058]gripper14 provided on theinner needle hub6 is gripped to retreat theinner needle hub6. Following the retreating, the front andrear enveloping portions23 and24 are rotated toward theouter needle hub4 and, further as shown in FIG. 12, completely expanded along theinner needle3 on both side faces of the same to be linear. Thus, when thesupport member7 is removed from theouter needle hub4, as shown in FIG. 13, the opened surfaces of the tub-shaped front andrear enveloping portions23 and24 face theinner needle3. As a result, the entireinner needle3 is enveloped by thefront enveloping portions23 and23, and therear enveloping portions24 and24 arranged on both sides of theinner needle3. Thus, it is possible to surely prevent the medical personnel or the worker engaged in needle disposal from accidentally sticking the knife point portion of theinner needle3, or touching theinner needle3.
• For explanation, only one[0059]front enveloping portion23 and onerear enveloping portion24 are shown in FIG. 13.
• In this case, the self-retaining[0060]needle21 comprises protrusion preventing means provided to prevent theknife point portion5 of theinner needle3 retreated into thesupport member7 once after theouter needle hub4 from being protruded again from thesupport member7. The protrusion preventing means can be similar in constitution to that of the self-retaining needle1 of the first embodiment.
• In the first embodiment, the[0061]front enveloping portion10 and therear portion12 are folded at thethin portion13. In the second embodiment, the front andrear enveloping portions23 and24 are folded at thethin portion25. However, thefront enveloping portion10, therear portion12, and the front andrear enveloping portions23 and24 may be folded through hinge portions made of mechanical components in place of thethin portions13 and25.
INDUSTRIAL APPLICABILITY
• The present invention can be applied to a self-retaining needle as a medical instrument, which is connected to an infusion device or the like for introducing blood, medicine or the like into a body of a patient.[0062]

Claims (18)

1. A self-retaining needle having a hollow outer needle, an outer needle hub provided in a base of the outer needle, a hollow inner needle having a knife point portion on a tip and a length of the knife point portion protruded from a tip of the outer needle when it is inserted from the outer needle hub into the outer needle, and an inner needle hub provided in a base of the inner needle and positioned at the rear of the outer needle hub when the knife point portion of the inner needle is protruded from the tip of the outer needle, comprising:

a support member for detachably supporting the outer needle hub in front of the inner needle hub; and

an enveloping member for connecting the support member with the inner needle hub and enveloping a front of the inner needle when the inner needle is retreated toward the rear of the outer needle hub,

wherein a front portion and a rear portion of the enveloping member are connected so as to be freely folded, said front portion is formed in a tub shape having a surface opposite the inner needle hub opened, and said rear portion is formed in a flat shape; when the knife point portion of the inner needle is protruded from the tip of the outer needle, the front portion and the rear portion of the enveloping member are folded, so that the rear portion is housed in said front portion formed in a tub shape; and when the inner needle is retreated toward the rear of the outer needle hub, and the front portion and the rear portion thereof are expanded along both side faces of the inner needle, the enveloping member envelops a front of the inner needle by the front portion.

2. The self-retaining needle according toclaim 1, wherein the front portion is rotatably attached to the support member at an end, the rear portion is rotatably attached to the inner needle hub at a rear end, and a rear end of the front portion and a tip of the rear portion are folded through a hinge portion.

3. (Deleted)

4. (Deleted)

5. (Deleted)

6. (Deleted)

7. The self-retaining needle according to any one of claims1 or2, further comprising protrusion preventing means for preventing the knife point portion of the inner needle from being protruded again when the inner needle is retreated toward the rear of the outer needle hub, and the front portion and the rear portion are expanded along both AMENDED SHEETS side faces of the inner needle.

8. The self-retaining needle according toclaim 7, wherein the protrusion preventing means includes a rotation guiding member, in which the rear portion of the enveloping member is rotatably attached to the inner needle hub, and the inner needle hub guides rotation of the rear portion, a slope portion formed to be gradually protruded from a surface of the guiding member, and a stepped portion provided on a boundary with the surface of the guiding member on a most protruded part of the slope portion, and the rear portion is positioned on a base of the slope portion in a folded state, guided and rotated by the slope portion following a laying-out operation, and engaged with the stepped portion by going over the most protruded part of the slope portion to prevent the knife point portion of the inner needle from being rotated again in a protruding direction.

9. The self-retaining needle according toclaim 7, wherein the protrusion preventing means includes a rotation guiding member, in which the rear portion of the enveloping member is rotatably attached to the inner needle hub, and the inner needle hub guides rotation of the rear portion, and a stepped portion formed on a side face of the rotation guiding member from outside to inside, the rear portion is rotated along the side face of the rotation guiding member following a laying-out operation from a folded state, and engaged with the stepped portion by moving from outside to inside on the side face of the rotation guiding member to prevent the knife point portion of the inner needle from being rotated again in a protruding direction.

10. The self-retaining needle according toclaim 7, wherein the protrusion preventing means includes a pair of upper and lower rotation guiding members, in which the rear portion of the enveloping member is rotatably attached to the inner needle hub, and the inner needle hub guides rotation of the rear portion, a groove portion provided on a surface of one rotation guiding member, and a protruded portion provided on a surface of the other rotation guiding member to face the groove portion, and the rear portion is guided and rotated by the rotation guiding member following a laying-out operation from a folded state, dropped into the groove portion, and prevented from being pulled out from the groove portion by the protruded portion, and an extended direction of the inner needle is inclined with respect to the support member.

11. The self-retaining needle according toclaim 7, wherein the protrusion preventing means includes a hollow chamber provided in the support member, and a spacing member provided with a through-hole for inserting the inner needle, and moved in the hollow chamber to incline the through-hole with respect to an extended direction of the inner needle when the inner needle is pulled out from the through-hole.

12. A self-retaining needle having a hollow outer needle, an outer needle hub provided in a base of the outer needle, a hollow inner needle having a knife point portion on a tip and a length of the knife point portion protruded from a tip of the outer needle when it is inserted from the outer needle hub into the outer needle, and an inner needle hub provided in a base of the inner needle and positioned at the rear of the outer needle hub when the knife point portion of the inner needle is protruded from the tip of the outer needle, comprising:

a support member for detachably supporting the outer needle hub in front of the inner needle hub; and

an enveloping member for connecting the support member with the inner needle hub and enveloping the inner needle when the inner needle is retreated toward the rear of the outer needle hub,

wherein a front portion and a rear portion of the enveloping member are connected so as to be freely folded, said front portion is formed in a tub shape having a surface opposite the inner needle hub opened, and said rear portion is formed in a tub shape having a surface opposite the opened surface of the front portion opened; when the knife point portion of the inner needle is protruded from the tip of the outer needle, the front portion and the rear portion of the enveloping member are folded, so that the rear portion is housed in said front portion formed in a tub shape; and when the inner needle is retreated toward the rear of the outer needle hub, and the front portion and the rear portion thereof are expanded along both side faces of the inner needle, the enveloping member envelops the inner needle by the front portion and the rear portion.

13. The self-retaining needle according toclaim 12, wherein the front portion is rotatably attached to the support member at an end, the rear portion is rotatably attached to the inner needle hub at a rear end, and a rear end of the front portion and a tip of the rear portion are folded through a hinge portion.

14. The self-retaining needle according to any one of claims12 or13, further comprising protrusion preventing means for preventing the knife point portion of the inner needle from being protruded again when the inner needle is retreated toward the rear of the outer needle hub, and the front portion and the rear portion are expanded along both side faces of the inner needle.

15. The self-retaining needle according toclaim 14, wherein the protrusion preventing means includes a rotation guiding member, in which the rear portion of the enveloping member is rotatably attached to the inner needle hub, and the inner needle hub guides rotation of the rear portion, a slope portion formed to be gradually protruded from a surface of the guiding member, and a stepped portion provided on a boundary with the surface of the guiding member on a most protruded part of the slope portion, and the rear portion is positioned on a base of the slope portion in a folded state, guided and rotated by the slope portion following a laying-out operation, and engaged with the stepped portion by going over the most protruded part of the slope portion to prevent the knife point portion of the inner needle from being rotated again in a protruding direction.

16. The self-retaining needle according toclaim 14, wherein the protrusion preventing means includes a rotation guiding member, in which the rear portion of the enveloping member is rotatably attached to the inner needle hub, and the inner needle hub guides rotation of the rear portion, and a stepped portion formed on a side face of the rotation guiding member from outside to inside, the rear portion is rotated along the side face of the rotation guiding member following a laying-out operation from a folded state, and engaged with the stepped portion by moving from outside to inside on the side face of the rotation guiding member to prevent the knife point portion of the inner needle from being rotated again in a protruding direction.

17. The self-retaining needle according toclaim 14, wherein the protrusion preventing means includes a pair of upper and lower rotation guiding members, in which the rear portion of the enveloping member is rotatably attached to the inner needle hub, and the inner needle hub guides rotation of the rear portion, a groove portion provided on a surface of one rotation guiding member, and a protruded portion provided on a surface of the other rotation guiding member to face the groove portion, and the rear portion is guided and rotated by the rotation guiding member following a laying-out operation from a folded state, dropped into the groove portion, and prevented from being pulled out from the groove portion by the protruded portion, and an extended direction of the inner needle is inclined with respect to the support member.

18. The self-retaining needle according toclaim 14, wherein the protrusion preventing means includes a hollow chamber provided in the support member, and a spacing member provided with a through-hole for inserting the inner needle, and moved in the hollow chamber to incline the through-hole with respect to an extended direction of the inner needle when the inner needle is pulled out from the through-hole.

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